TiO_2负载Cu-Mn复合氧化物催化燃烧正己醛

Catalytic Combustion of n-Hexanal Using Cu-Mn Composite Oxide Supported on TiO_2

通过调控Cu负载量及Cu/Mn原子比,探究其对TiO_2负载Cu-Mn复合氧化物(Cu_xMn_y/TiO_2)催化材料中活性组分间相互作用的影响,结果表明,铜负载量为15%(w,质量分数)和Cu/Mn原子比为1:1时有利于类铜锰尖晶石相Cu_(1.5)Mn_(1.5)O_4的形成,随着Cu负载量的增加促使氧物种从晶格氧向表面吸附氧转移。复合催化材料中铜负载量的变化及Cu/Mn原子比对活性组分和催化活性间的相互作用影响显著。结果发现Cu_(15)Mn_(15)/TiO_2在225°C时使正己醛转化率达到90%(T_(90)),材料良好的性能归因于其具有较高的Cu^(2+)与O_(ads)含量,并可与Mn^(2+)实现双还原氧化过程。结果表明,Cu_(15)Mn_(15)/TiO_2复合材料中的类铜锰尖晶石活性组分可完成redox循环,以保持催化材料较高的稳定性。

In this study, we regulated copper loading and the atomic ratio of Cu/Mn and investigated the influence on interaction of the active species of Cu-Mn composite oxide catalyst supported on TiO2 （CuxMny/TiO2）. The results indicate that 15% （w, mass fraction） copper loading and a 1 ： 1 atomic ratio of Cu/Mn favors formation of analogous Cu-Mn spinel （Cu1.5Mn1.5O4）. With increasing loading of copper, oxygen transfers from the lattice oxygen species to defect oxygen. The changes in copper loading and the Cu/Mn atomic ratio have a large influence on the interaction between the active components and the catalytic activity. We found that 90% n-hexanal can be degraded by Cu15Mn15/TiO2 at 225 ℃ （7-90）. The excellent performance of Cu15Mn15/TiO2 is attributed to the higher contents of Cu^2＋ and Osds, which can achieve a dual redox process with Mn^2＋ in Cu15Mn15/TiO2. The analogous Cu-Mn spinel active ingredient can maintain high catalytic stability by redox cycles.